Capsule endoscopy is a procedure that uses a tiny wireless camera to take pictures of your digestive tract. A capsule endoscopy camera sits inside a vitamin-size capsule you swallow. As the capsule travels through your digestive tract, the camera takes thousands of pictures that are transmitted to a recorder you wear on a belt around your waist.

Capsule endoscopy helps doctors see inside your small intestine — an area that isn't easily reached with more-traditional endoscopy procedures. Traditional endoscopy involves passing a long, flexible tube equipped with a video camera down your throat or through your rectum.

Capsule endoscopy has also been approved for the screening of the colon for colon polyps for those for whom a colonoscopy couldn't be completed. But how and on whom it will be used is still being determined because better alternatives are available. As technology improves, capsule endoscopy of the colon may be used more in the future.

Capsule endoscopy has also been approved to evaluate the muscular tube that connects your mouth and your stomach (esophagus) to look for abnormal, enlarged veins (varices). It's rarely used because experience with it is limited and traditional upper endoscopy is widely available.

Your doctor might recommend a capsule endoscopy procedure to:

Find the cause of gastrointestinal bleeding. If you have unexplained bleeding in your digestive tract, capsule endoscopy can help find the cause.

Diagnose inflammatory bowel diseases, such as Crohn's disease. Capsule endoscopy can reveal areas of inflammation in the small intestine.

Diagnose cancer. Capsule endoscopy can show tumors in the small intestine or other parts of the digestive tract.

Diagnose celiac disease. Capsule endoscopy is sometimes used in diagnosing and monitoring this immune reaction to eating gluten.

Screen for polyps. People who have inherited syndromes that can cause polyps in the small intestine might occasionally undergo capsule endoscopy.

Do follow-up testing after X-rays or other imaging tests. If results of an imaging test are unclear or inconclusive, your doctor might recommend a capsule endoscopy to get more information.

Capsule endoscopy is a safe procedure that carries few risks. However, it's possible for a capsule to become lodged in the digestive tract rather than leaving your body in a bowel movement within several days.

The risk, which is small, might be higher in people who have a condition — such as a tumor, Crohn's disease or previous surgery in the area — that causes a narrowing (stricture) in the digestive tract. If you have abdominal pain or are at risk of a narrowing of your intestine, your doctor likely will get a CT scan to look for a narrowing before using capsule endoscopy. Even if the imaging study is negative, there's still a small chance that the capsule could get stuck.

If the capsule hasn't passed in a bowel movement but isn't causing signs and symptoms, your doctor might give the capsule more time to leave your body. However, a capsule causing signs and symptoms that indicate bowel obstruction must be removed, either by surgery or through a traditional endoscopy procedure, depending on where the capsule is stuck.

To prepare for your capsule endoscopy, your doctor is likely to ask that you:

Stop eating and drinking at least 12 hours before the procedure. This will ensure that the camera captures clear images of your digestive tract.

Stop or delay taking certain medications. To keep medication from interfering with the camera, your doctor might ask you not to take certain medications before the procedure. In other cases, your doctor will want you to take your medication two hours before or after you swallow the camera capsule that contains the camera.

Plan to take it easy for the day. In most cases, you'll be able to go about your day after you swallow the camera capsule. But you'll likely be asked not to do strenuous exercise or heavy lifting. If you have an active job, ask your doctor whether you can go back to work the day of your capsule endoscopy.

In some cases, your doctor may ask you to take a laxative before your capsule endoscopy to flush out your small intestine. This has been shown to improve the quality of the pictures collected by the capsule's camera.

Follow your doctor's instructions in preparing for your capsule endoscopy. Failure to follow the directions may mean your capsule endoscopy may need to be rescheduled.

On the day of your capsule endoscopy, your health care team will review the procedure. You might be asked to remove your shirt so that adhesive patches can be attached to your abdomen. Each patch contains an antenna with wires that connect to a recorder. Some devices don't require the patches.

You wear the recorder on a special belt around your waist. The camera sends images to an antenna on your abdomen, which feeds the data to the recorder. The recorder collects and stores the images.

Once the recorder is connected and ready, you swallow the camera capsule with water. A slippery coating makes it easier to swallow. Once you swallow it, you shouldn't be able to feel it.

You'll then go about your day. You can drive, and you might be able to go to work, depending on your job. Your doctor will discuss restrictions, such as avoiding strenuous activity, such as running and jumping, with you.

After the capsule endoscopy

Wait two hours after you swallow the capsule to resume drinking clear liquids. After four hours, you can have a light lunch or a snack unless your doctor tells you otherwise.

The capsule endoscopy procedure is complete after eight hours or when you see the camera capsule in the toilet after a bowel movement, whichever comes first. Remove the patches and the recorder from your body, pack them in a bag and follow your doctor's instructions for returning the equipment. You can flush the camera capsule down the toilet.

Your body might expel the camera capsule within hours or after several days. Each person's digestive system is different. If you don't see the capsule in the toilet within two weeks, contact your doctor. Your doctor might order an X-ray to see if the capsule is still in your body.

The camera used in capsule endoscopy takes thousands of color photos as it passes through your digestive tract. The images saved on the recorder are transferred to a computer with special software that strings the images together to create a video. Your doctor watches the video to look for abnormalities within your digestive tract.

It might take a few days to a week or longer to receive the results of your capsule endoscopy. Your doctor will then share the results with you.

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